The Vault 77 Jumpsuit is a standard Vault Jumpsuit in Fallout 3, wearing it adds 5 skill points to Unarmed and Melee Weapons. Despite the appearance of the jumpsuit, Vault 77 doesn't appear in any of the Fallout games, it refers to a Penny Arcade comic strip.

The Jumpsuit is found alongside a holotape from an unknown slaver who says that the stories surrounding the Vault 77 Jumpsuit are scaring some of the slavers. According to the Penny Arcade comic, the former owner of this Jumpsuit, known as the Puppet Man, killed several Slavers and wiped out a whole camp of them before disappearing.

The slavers are also apparently very unnerved by the presence of the Jumpsuit, as the slaver in the holotape says the man may come back for it even though he should be dead according to the comic.